Fig. 2

Schematic representation of the process. 1. Bioconversion medium. 2. Addition of filter-sterilized 1,3-PDO. 3. Manual valve opened when bioconversion starts. 4. Feed pump, activated depending on pH measurements. 5. Alkali and substrate mix. Solid arrows indicate fluid streams while dotted lines indicate electronic signals. M. Stirring motor. IRC. Indicator, recorder and controller of the concerned parameter [pH, pO₂, temperature (T)]. WIR. Weight indicator and recorder